Kim Kardashian has slammed a YouTuber whose prank fooled the internet into believing Kylie Jenner's boyfriend was cheating on her.

On Monday (local time), a photo made the rounds on social media that showed a man who looked like Travis Scott, the 26-year-old rapper and father of Jenner's child, embracing a scantily clad woman on a balcony.

The image immediately prompted rumours of infidelity, which Scott denied in a post to his Instagram story.

Now it's been revealed that the image was a staged photo created by YouTuber Christian Adam, a 19-year-old with more than 300,000 subscribers.

On Wednesday (local time) he posted a video titled 'We Fooled the Internet w/ Fake Travis Scott Cheating Photo'. During the 17-minute clip he detailed how he dressed up as Scott and posed with a female friend on a balcony, and had another friend take paparazzi-style pictures of them together.

He then circulated the misleading image online with a fake TMZ watermark over the top - and it didn't take long for it to be picked up by gossip websites.

The video description contains a disclaimer that he did not intend to hurt Scott, Jenner nor any other member of their extended family.

While many YouTube commenters applauded Adam for his audacity and manipulation of the media, others were less impressed - namely Scott's girlfriend.

Jenner, 21, posted a screenshot of the video to her own Instagram story, and wrote: "Idk if this is really a social experiment to some people but you're messing with real people, real relationships, real family.

"I'm happy my relationship is strong because this is getting out of hand. The internet scares me sometimes for real."